Explanation:
Where did all these high energy positrons come from?
The Alpha Magnetic Spectrometer (AMS-02) onboard the
International Space Station (ISS)
has been meticulously recording how often it is struck by both high energy electrons and
positrons since 2011.
After accumulating years of data, it has now become clear
that there are significantly more positrons than expected
at the highest energies detected.
The excess may have a very exciting and profound origin -- the annihilation of distant but previously undetected dark matter particles.
However, it is also possible that astronomical sources such as
pulsars
are creating the
unexplained discrepancy.
The topic remains a very active area of research.
Pictured here, the
AMS is visible on the ISS just after being installed, with a US
Space Shuttle docked on the far right, a Russian
Soyuz capsule docked on the far left, and the
blue Earth that houses all nations visible across the background.